A Direct and an Efficient Regioselective Synthesis of 1,2-Benzothiazine 1,1-dioxides, β-Carbolinones, Indolo[2,3-]pyran-1-ones, Indolo[3,2-]pyran-1-ones, Thieno[2,3-]pyran-7-ones and Pyrano[3',4':4,5]imidazo[1,2-]pyridin-1-ones via Tandem Stille/Heterocyclization Reaction.

A general regioselective one-pot synthesis of 1,2-benzothiazine 1,1-dioxides from 2-iodo benzenesulfonamide moieties and allenylstannanes is described using a domino Stille-like/Azacyclization reaction. The conditions developed also opened a novel access to β-carbolinones, indolopyranones, thienopyranones and pyrano-imidazopyridines.

Regioselective copper-mediated synthesis of thieno[2,3-c]pyrane-7-one, indolo[2,3-c]pyrane-1-one, and indolo[3,2-c]pyrane-1-one.

In the presence of copper(I) iodide, heteroaromatic β-iodo-α,β-unsaturated carboxylic acid systems opposed to terminal alkyne afford selectively 6-endo-dig cyclization products via a tandem coupling oxacyclization reaction.